Combination drill collar and turbine driven bit



J. H. MARTIN Feb. 20, 1962 COMBINATION DRILL COLLAR AND TURBINE DRIVEN BIT Original Filed Oct. 15, 1956 4/0/2/7 H. Mar/#7 INVENTOR- BYZUZ .$.M

ATTORNEY This invention relates to the combination of a drill collar and turbine driven bit of the type designed to employ the drilling fluid or circulation mud now employed in the rotary method of drilling wells to supply force to rotate the bit in drilling, this application being a continuation application of co-pending application Serial No. 616,084, now abandoned, filed October 15, 1956 for Combination Drill Collar and Turbine Driven Bit and Method of Drilling Therewith.

It is a primary object of this invention to provide a combination drill collar and turbine driven bit of the class in Which force to drive a turbine in the drill collar may be employed through a unique drive to impart rotation to the bit while at the same time providing for the circulation of the fluid through the bit.

It is another object of this invention to provide a combination drill collar and turbine driven bit of this class which transfers the rotative force of the turbine through an anti-friction equipped transmission to drive the drill bit.

It is still another object of this invention to provide a combination drill collar and turbine driven bit of this class which is adapted to divert excess fluid delivered down the drill stem at excess pressure so that such does not pass through the turbine to impart excess rotation to the bit.

It is also another object of this invention to provide an apparatus for drilling a well employing the circulation fluid or drilling mud to drive a turbine which supplies force to rotate the bit while at the same time rotation is imparted to the drill stem for purposes of agitating the circulating medium in the well bore annulus, tending to maintain the well bore straight, and the like.

Other and further objects will be apparent when the specification herein is considered in connection with the drawings in which:

FIG. 1 is a sectional elevation of an embodiment of a combination drill collar and turbine driven bit displaying a form of the invention;

FIG. 2 is a sectional plan view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional plan view taken along line 3-3 of FIG. 1; and

FIG. 4 is a sectional of FIG. 1.

Referring in detail to the drawings in which likereference numerals are applied to corresponding elements in the various views, a drill stem 11, as employed in the rotary method of drilling wells is shown having a drill collar and turbine driven bit assembly 12 attached to the lower end thereof by means of an adapter 14 having its pin end 15 threadably engaged in the box end 16 at the lower end of the drill stem 11, while the lower end of the adapter is threadably engaged at 17 with the internally threaded upper end of the drill collar 18.

Spaced below the adapter 14, the drill collar 18 has outer turbine blades 19 afiixed to the upper inner surface thereof, such as by interfitment of outer parts thereof into keyways 20 in the inner surface of the drill collar 18.

A shaft 21 has an upper end 22 journalled in a bore in I the lower face of the adapter 14 and concentric with the longitudinal axis of the drill collar 18, such end having ample bearing length. Roller bearings 23 are provided plan view taken along line 4-4.

as anti-friction means to bear against the upper endof the shaft 22 in rotation. :I

Fluid passages 24 are provided in the adapter 14 to establish fluid communication between the drill stem bore 25 and the drill collar interior 26 therebelow. Below its upper end 22 the shaft 21 has larger diameter portion 26 and therebelow a still larger diameter portion 27 to thereby provide a shoulder 28 to support thereon the inner part of a turbine 29 having blades 31 which cooperate with the outer turbine blades 19 in the inner periphery of the drill collar 12, such inner blades 30 being fixed to rotate with the shaft 21, as by being keyed or pinned thereto. The turbine arrangement including the blades 19 and 36 is shown partially diagrammatically and such construction of the turbine, including its blades, is conventional and of the type well designed to rotate the shaft 21 with substantial velocity as the turbine blades 30 are driven by the passage of circulation fluid or drilling mud therethrough.

Upon passage through the turbine 29 the fluid may pass downwardly through the inlet 31 in the shaft portion 27 and down a longitudinally extending fluid passage 32 therein and out the lower end of a shaft 21. In case of the pump at the top of the well operating with excess pressure, so that it may tend to drive the turbine blades 31) at excessive speed, a by-pass assembly 33 is provided at the top of the turbine 29.

Such assembly includes an outer cup 34 which seats on the top of the upper turbine blade 30 and provides a central bore therein into which may be fitted a reduced diameter lower end part 35 on a sleeve 36 which extends around the upper end of the shaft portion 26. Such sleeve has sealing rings 37 in grooves in the upper and lower ends thereof and between such sealing rings it has ports 38' in the side wall thereof. The upper end of the shaft portion 26 is threaded and has a hold-down nut 46 thereon to firmly force the sleeve 36 against the cup 34 and against a rubber cup 38 between the sleeve 36 and cup 34, such rubber cup 38 being held down by the sleeve 36 as it shoulders thereon at 39, the bottom of the cup 38 bearing firmly against the inner surface of the cup 34.

The cup 38 has its side wall tapered inwardly andupwardly upon its outer periphery and is of such material, as rubber, so that it has expansibility. It follows that when the speed of rotation of the shaft 21 exceeds a certain pre-determined rate, centrifugal force will act on the cup 38 to force the upper part thereof outwardly to uncover ports 38' so that the excess of fluid may pass into the shaft portion 26 through radial ports 41 and down an axially extending bore 42 in such shaft portion to communicate with the bore 32 through the shaft portion 27 therebelow. Thus the undesired effects of excessive fluid pressure operating through the blades 19, 30 may be avoided so that the turbine 29 may not be over driven beyond its designed limits.

The shaft portion 27 is journalled at 43 in a reduced inner diameter portion 43 of the drill collar 18. Ball bearings 44 are provided in complementary annular grooves in the shaft portion 27 and drill collar ring 43, access being had through bored and counter-bored holes 45 through the drill collar wall to receive set screws 46 threadably into the bores, such set screws having reduced diameter shanks 47 to extend into the counter-bores and restrain the balls 44 from outward passage.

The shaft portion 27 includes a portion 48 of a smaller diameter which is eccentric with relation to the longitudinal axis of the drill collar and of the shaft 21 including the upper part of the shaft portion 27. As shown in FIG. 2' and in FIG. 1, an upper ring of roller bearings 49 are provided in an annular groove about the eccentric shaft portion 48 and a planetary gear 56 has its inner periphery in contact with the outermost surfaces of Patented Feb. 2a, 1962 the roller bearings 49. Thus the rotation of the shaft 21, as driven by the turbine 29, may be imparted through the roller bearings 49 to tend to rotate the planetary gear 50. Then since the drill collar 18, which at this point is outwardly and inwardly eccentric with relation to the axis of the eccentric portion 48 of the shaft 21, has internal teeth 51 cut therein and concentric with the axis of the drill collar and since such teeth 51 are cut to mesh with the teeth 59' such teeth must be one or more in excess of the teeth 50. Consequently the rotation of the eccentric shaft portion 48 rotates the roller bearings 44 and at the same time forces them to contact the bore of the gear i), and as the eccentric portion 48 is rotated, the teeth 50 of the gear 50 are pushed into mesh with the internal teeth 51 of the drill collar 18 with an obviously positive wedging action whereby rotation is imparted to the gear 59.

The planetary gear 59 is of composite structure and has a lower portion having teeth 52 thereon which may or may not be of the same number as the teeth 50' thereabove. A similar roller bearing assembly 49 is provided between the eccentric shaft portion 48 and the interior surface of the lower part of the planetary gear 50 and provides an anti-friction means at this elevation. A driving connection member 53 is provided and journalled Within the lower, enlarged inner diameter part 54 of the drill collar 18, such connection 53 being concentric with the axis of the drill collar and concentric with the axis of the shaft 21. The connection 53 has an'upper part 55 which has internal teeth therein, as the teeth 56. Such teeth may be equal in number to the teeth 52 and of the configuration shown in FIG. 3, or they may be of a different number, as a greater number, in which case a slight speed reduction would take place as the planetary gear 50 through its lower teeth 52, may drive the connection member 53 around within the lower part 54 of the drill collar 18. Below its upper part 55 the driving connection member 53 has a reduced diameter bore therethrough concentric with the axis of the drill collar 18 and of the shaft 21 to receive therein the lower end 57 of the shaft 21 so that such lower end must be concentric with the axis of the drill collar 18 and of the shaft 21, and thus eccentric with relation to the eccentric shaft portion 48.

Roller bearings 49 are provided in the driving con nection 53 as shown in FIG. 4 to minimize friction about the shaft end 57. Also friction between the driving connection 53 and the lower end 54 of the drill collar is minimized by means of ball bearings 58 and 58 and also 58 vertically spaced apart in complementary annular grooves as best shown in FIG. 1; access being had to such ball bearings through bores 45' and counter-bores 47' through which the set screws 46 are inserted to hold the ball bearings against escape.

In order to protect the transmission through the shaft portion 27 and driving connection 53 from being injured by the drilling mud or circulation fluid passing therethrough to score the parts thereoflsealing rings are provided in suitable grooves in the connection member 53; one such ring 37 being provided between the inner periphery of the connection member 53 and the lower end 57 of the shaft 21; one such sealing ring being provided between the lower end 54 of'the drill collar and the lower end of the driving connection 53; and one such sealing ring 37 being provided between the shaft por-' tion 27 and the drill collar 18 just below the inlet 31 into the shaft portion 27.

The lower end of the driving connection member 53 is internally threaded at 59 concentric with the axis of the shaft 21 and the axis of the drill collar 18 to receive therein the pin or upper part 61 of a bit 60. Such bit is shown partially diagrammatic as being of the conventional drilling bit construction having cones or cutters 62 rotatably mounted thereon such cutters usually being mounted in opposed pairs. The bore'or passage 32 through the shaft portion 27 establishes fluid communication with a passage or a plurality of passages passing downwardly through the bit to eject fluid between the cones, on the cones, or centrally inwardly thereof. Types of bits may be such as shown in Greve Patent No, 1,918,- 096, issued July 11, 193 in which jet passages are provided radially outwardly of the central axis through the bit. Another type of bit employable is that to Appleby as disclosed in Patent No. 2,307,658, issued January 5, 1943. Still another type of bit of earlier design may be that shown in Humas'on, Patent No. 1,294,106, issued February 11, 1919. Also any number of conventional bits may be employed having various passage arrangements therethrough.

In service a drill collar 12 with the hereinabove described assembly is connected to a drill stem 11 and in the well bore the conventional drilling mud or circulating fluid is pumped down the bore 25 to flow through the assembly and out the passage means through the bit 6t} to flow up the annular space between the well bore and drill stern and out into a reservoir or mud pit at the top of the well where it is picked up by conventional powerful circulation pumps and re-delivered down the drill stem bore 25. The flow of the pressurized fluid through the turbine 29 rotates the inner blades 30 after the fashion of conventional turbine operation and the transmission is efiected by the rotation of such shaft being transmitted through the upper roller bearings 49 to the planetary gear 50 which must rotate as confined eccentrically within the relatively stationary drill collar 13 and the shaft 21 which is driven by the turbine to rotate at a high velocity. The rotation of the planetary gear 56 is imparted through its lower teeth 52 to the upper end 55 of the driving connection member 53 to rotate this member as it is constrained between the lower end 54 of the drill collar and its'contact with the lower part of the planetary gear 50 through the gear teeth 52. The driving connection member 53 is thus positively rotated and must rotate the'drilling bit 60 therewith.

It often occurs in the rotary method of drilling well bores that due to variation in the hardness of the formations penetrated, and other factors, that well bores do not extend vertically but rather follow tortuous or cork screw paths through the earth. In case of drilling with a stationary drill stern whereby the bit 68 is rotated only due to the driving force developed in fluid passage through the turbine 29 the well bore can take an even more tortuous path as there is no rotation of the drill stem to wear away the turns in the formation to tend to keep the well bore straighter. For this reason, and for others to be set forth hereinbelow, it will be found expedient, at least in drilling in certain formations, to impart some degree of rotation to the drill stern. v

For instance some degree of drill stem rotation is advised; because otherwise'when the drill'stem is stationary the fluid circulates vertically up the well bore annulus, but there is no swirling of the fluid as'would occur when the drill stem is rotated. However, without such agitation or swirling, the slower moving of the fluid with relation to the well bore enables the fluid toform a filter cake on the face of the well bore in shorter time than may be desirableunder many circumstances.

In addition to avoiding the tendency to form a filter cake too quickly, slight rotation of the drill stem tends to cause a straighter hole to be drilled than would be drilled if the drill stern were not rotated as the turbine driven bit drills the well bore since by rotation the drill stem tends to wear away and straighten out irregularitiesor twists in the well bore made by the bit and drill collar, as these elements may be deflected from the true vertical by such influences as the heterogeneous nature of the penetrated formations. However the degree of rotation recommended, as set forth hereinabove, does not compare in costs with regular drilling costs, since the employment of the drawwork's of the rig is greatly reduced by placing the main load of rotating the bit upon the turbine, as driven by the circulating fluid or drilling mud. Thus the drilling fluid, which has to be provided in any event for purposes such as weighting the well to reduce hazards of .blowouts due to excessive hydrostatic pressure from below, serves in dual capacity as it drives the turbine at no increased cost.

By this method of adding slight drill stem rotation, and in the same direction of rotation as the bit is driven, which must be generally the direction of pipe section make-up, the force exerted in such slight drill stem rotation is additive to the drilling force developed by the turbine and consequently very effective drilling operation may be carried out by this method.

Broadly this invention relates to a structure through which fluid circulation may be employed to drive the drilling bit in drilling a well and it also relates to an apparatus for drilling whereby the conventional rotary table at the top of the well may be employed to slowly rotate the drill stem carrying such structure to thereby add to the drilling.

effect while obtaining the advantages of drill stern rotation. The invention is not limited to the structure herein disclosed, nor to the exact method of employment but other structures and methods are considered as well as such may fall within the broad spirit of the invention and within the broad scope of interpretation claimed. and merited for the appended claims.

What is claimed is:

l. A tubular drill collar and turbine driven bit assembly for employment on the end of a drill stem in the rotary method of drilling wells, as oil wells, said assembly comprising a tubular drill collar adapted at its upper end for connection to said drill stem and to establish fluid communication between the drill collar and drill stem interiors and having successively from upper end toward lower end, inwardly extending, vertically spaced apart, outer turbine blades positioned therein, an inwardly extending ring, and internal gear teeth concentrically formed therein below said ring, a shaft having a central portion extending upwardly through said ring and thereabove, and a shaft portion below said central portion and eccentric to said ring, an anti-friction means connecting said central portion and said ring for relative rotation and to inhibit axial movement therebetween, said shaft providing a flow passage from said drill collar interior above said ring into said central portion and on through the lower end of said shaft, and said shaft also having outwardly extending, vertically spaced, inner turbine blades supported above said central portion to extend with turbine blade cl arance into the interstices between said outer turbine blades, a planetary ring gear having upper and lower external gear teeth formed thereon and said ring gear being positionable upon said eccentric portion to be drivingly engaged thereby with part of said upper ring gear teeth to be progressively in mesh with said drill collar teeth and part thereof progressively spaced therefrom, a tubular driving connection member positionable within the lower end of said drill collar and having a recess in the upper end thereof to provide a shoulder to support said ring gear and constrain it between said drill collar ring and said shaft central portion thereabove and said shoulder therebelow, an anti-friction means connecting said drill collar and said driving connection member for relative rotation and to inhibit axial movement therebetween, and a drilling bit connected to the lower end of said driving connection member and having flow passage means extending upwardly therethrough within said drill collar and to establish fluid communication with the lower end of said shaft flow passage, whereby pressure fluid pumped down said drill stern thus passes through said turbine blades to rotate said shaft to drive through said planetary ring gear as it meshes with said drill collar teeth and rotates said driving connection member and said drilling bit therewith in drilling.

2. A tubular drill collar and turbine driven bit assembly as claimed in claim 1 in whicha fluid seal is provided between said drill collar ring and said shaft central portion thereabove above said anti-friction means which connects such elements, in which a fluid seal is provided be tween said drill collar and said driving connection member below said anti-friction means which connects such elements, and in which a fluid seal is provided between said driving connection member and the lowermost part of said shaft at substantially the lower end thereof.

3. A tubular drill collar and turbine driven bit assembly as claimed in claim 1 in which a relief flow passage is provided into said shaft at an elevation above said turbine blades to pass downwardly through said shaft to join said first flow passage therethrough, a flexible cup supported above said turbine blades flexed at normal fluid pressures to occlude said relief flow passage, and extendible responsive to excessive fluid pressures to permit pressure fluid to pass into said relief flow passage thereby reducing the pressure of fluid passing through said turbine blades and slowing down the rate of rotation thereof.

4. A tubular drill collar and turbine driven bit assembly for employment on the end of a drill stem in the rotary method of drilling wells, as oil wells, said assem-,

bly comprising a tubular drill collar adapted at itsupper end for connection to said drill stem and to establish fluid communication between the drill collar and 'drill stem interiors and having successively from upper end toward lower end, inwardly extending, vertically spaced apart, outer turbine blades positioned therein, an. inwardly extending ring, and internal gear teeth concentrically formed therein below said ring, a shaft having a central portion extending upwardly through said ring and thereabove,.and a shaft portion below said central portion and eccentric to said ring, means positioning said shaft to rotate within said ring and to inhibit relative axial movement between said shaft and said'ring, said shaft providing a flow passage from said drill collar interior above said ring into said central portion and on through the lower end of said shaft, and said shaft also having outwardly extending, vertically spaced, inner turbine blades supported above said central portion to extend with turbine blade clearance into the interstices between said outer turbine blades, a planetary ring gear having upper and lower external gear teeth formed thereon and said ring gear being positionable upon said eccentric portion to be drivingly engaged thereby with part of said upper ring gear teeth to be progressively in mesh with said drill collar teeth and part thereof progressively spaced therefrom, a tubular driving connection member positionable within the lower end of said drill collar and having a recess in the upper end thereof to provide av shoulder to support said ring gear and constrain it between saiddrill collar ring and said shaft central portion.

thereabove and said shoulder therebelow, an anti-friction means connecting said drill collar and said driving connection member for relative rotation and to inhibit axial movement therebetween, and a drilling bit connected to the lower end of said driving connection member and having flow passage means extending upwardly therethrough within said drill collar and to establish fluid communication with the lower end of said shaft flow passage, whereby pressure fluid pumped down said drill stem thus passes through said turbine blades to rotate said shaft to drive through said planetary ring gear as it meshes with said drill collar teeth and rotates said driving connection member and said drilling bit therewith in drilling. V

5. A tubular drill collar and turbine driven bit assembly for employment on the end of a drill stem in the rotary method of drilling wells, as oil wells, said assema bly comprising a tubular drill collar having a head adapted for connection to said drill stem and to establish fluid communication between the drill collar and drill stem interiors and having successively below said head from upper end toward lower end, inwardly'extending,

teeth concentrically formed therein below said ring, -a shaft having a central portion extending upwardly through said ring and thereabove, and a shaft portion below said central portion and eccentric to said ring and providing a flow passage from said drill collar interior above said ring into said central portion and on through the lower end of said shaft, and said shaft also having outwardly extending, vertically spaced, inner turbine blades supported above said central portion to extend with turbine blade clearance into the interstices between said outer turbine blades, a planetary ring gear having upper and lower external gear teeth formed thereon and said ring gear being positionable upon said eccentric portion to be drivingly engaged thereby with part of said upper ring gear teeth to be progressively in mesh with said drill collar teeth and part thereof progressively spaced therefrom, a tubular driving connection member positionable within the lower end of said drill collar and having a recess in the upper end thereof to provide a shoulder to support said shaft and said ring gear and to constrain said gear between said drill collar ring and said shaft central portion thereabove and said shoulder therebelow, while said head provides a recess therein to rotatably receive the upper end of said shaft in. constrained relation, ananti-friction means connecting said drill collar and said driving connection member for relative rotation and toinhibit axial movement therebetween, and a drilling bit connected to the lower end of said driving connection member and having flow passage means extending upwardly therethrough within said drill collar and to establish fluid communication with the lower end of said shaft flow passage, whereby pressure fluid pumped down said drill stem thus passes through said turbine blades to rotate said shaft to drive through said planetary ring gear as it meshes with said drill collar teeth and rotates said driving connection member and said drilling bit therewith in drilling.

6. A tubular drill collar and turbine driven bit assembly as claimed in claim in which a fluid seal is provided between said drill collar and said driving connection member below said anti-friction meanswhich connects such elements, and in which a fluid seal is provided between said driving connection member and the lowermost part of said shaft at substantially the lower end thereof.

7. A tubular drill collar and turbine driven bit assembly as claimed in claim 50in which a relief flow passage is provided into said shaft at an elevation above said turbine blades to pass downwardly through said shaft to join said first flow passage therethrough, a flexible cupsupported above said turbine blades flexed at normalfluid pressures to occlude said relief flow passage, and extendible responsive to excessive fluid pressures to permit pressure fluid to pass into said relief flow passage thereby reducing the pressure of fluid passing through J said'turbine blades and slowing down the rate of rotation thereof.

8. A tubular drill collar and turbine driven bit assembly for employment on the end of a drill stem in the rotary method of drilling wells, as oil wells, said assembly comprising a tubular drill collar adapted upwardly for connection to said drill stem to establish fluid communication therewith, and having successively below said connection outer turbine blades extending inwardly, an inwardly extending ringand internal gear teeth concentrically formed therein, said assembly also including an axially extending shaft having inwardly extending, vertically spaced apart, inner turbine blades supported thereon above said ring'to extend with turbine blade clearance into the interstices between said outer turbine blades, said shaft also having a portion extending through said ring concentrically therewith and having therebelow a portion eccentric to said concentric portion, a planetary gear mounted on the eccentric portion of said shaft with upper teeth thereon with part to mesh progressively with said drill collar teeth and with part to beprogressively spaced therefrom, and with lower teeth therebelow, a flow passage opening into said shaft between said blades I and said ring and extending downwardly therethrough,

a connection member, anti-friction means rotatably connecting said connection member to said drill collar, seal means below said anti-friction means to effect a seal between said connection member and said drill collar, said connection member having internal teeth therein upwardly with said lower teeth in part to mesh progressively therewith and'with part to be progressively spaced therefrom, said connection member having a shoulder therein to support said planetary gear, an anti-friction means between said concentric shaft portion and said ring to rotatably support said shaft against axial movement, and a hollow drilling bit connected to the lower end of said connection member to establish fluid communication with said flow passage whereby pressure fluid pumped down said drill stem' thus passes through said turbine blades to rotate said shaft to drive through said planetary ring gear as it meshes with drill collar teeth and rotates said connection member and said drilling bit therewith in drilling.

References Cited in the file of this patent UNITED STATES PATENTS 2,044,349 Diehl June 16, 1936 2,303,365 Karlsen Dec. 1, 1942 2,646,814 Mueller July 28, 1953 2,730,217 Bower Jan. 10, 1956 

